“Regarding your case of right aortic artery arch, I might say that while an anomalous right subclavian artery does cause oesophageal obstruction, which is not commonly associated with right aortic arch, and unless you have some definite reason to suspect this combination, I think the obstruction is more likely to be cause by the obliterated ligamentum arteriosum which passes from the right arch to the left pulmonary artery behind the oesophagus and trachea, and has been known to cause obstruction in a number of cases…”